Color temperature is known as a parameter for a display device such as a monitor of a television set or an electronic device, or the like. Whether under a fluorescent lamp of a daylight color, under a fluorescent lamp of an electric bulb color, under direct sunlight, or the like, the look of a screen may become greatly different depending on the strength or weakness of the light of a peripheral environment. Each environment has a different color temperature. Human eyes adjust themselves to the change of the color temperature and can distinguish color. If human eyes look at a paper which is seen as white under direct sunlight, the paper appears to have a red hue. With a time lapse, the paper looks white. This characteristic of human eyes is called “chromatic adaptation”.
Accordingly, in order to acquire color which is closer to the original color of an article displayed on the screen, it is demanded to properly adjust the color temperature of the display device. In a case of displaying an image seen as white under direct sunlight on the display device under the fluorescent lamp of an electric bulb as its natural color, the image may look blue to human eyes.
Conventionally, a display device, which can automatically execute an adjustment of the color temperature, is proposed.
However, in a case in which an image as a display target is changed and brightness becomes different between moment before and after the image changes, the change of the color temperature of the display device may appear artificial to human eyes.
When the display target is changed from a bright image to a dark image, for human eyes, the color temperature may be adjusted unnaturally as if the color temperature is suddenly changed. Human eyes easily follow the change from the dark image to the bright image, but do not easily follow its opposite change.